Described herein is a support structure for a load measurement sensor, and particularly, a support structure for a load measurement sensor which is supported while an extension portion extending from a sensor body is positioned at a side portion of the sensor body.
With a view to improving the safety of a passenger or the comfort thereof when the passenger sits on a seat, there is proposed a technique of controlling an operation of a device around a vehicle seat in response to the weight of the sitting passenger.
In such a technique, in order to detect the weight of the sitting passenger, a load measurement sensor is generally disposed below the vehicle seat on which the passenger sits.
The installation position of the load measurement sensor is generally located below the vehicle seat. Then, for example, there is a known configuration in which a load measurement sensor is installed between a seat frame constituting a vehicle seat and a slide rail installed to slide the vehicle seat in the front-to-back direction (see Japanese Patent Document No. 4205028B1 (“the '028 Reference”)).
The '028 Reference discloses, as illustrated in FIG. 27, a configuration in which a load measurement sensor 130 (which it describes as a “load sensor”) is installed above an upper rail 112 (which it describes as a “slider”) sliding on a lower rail 111 (which it describes as a “rail body”) attached to a vehicle body floor and a seat frame 101 is disposed above the load measurement sensor 130. Furthermore, FIG. 27 is a partial perspective view illustrating a vehicle seat which adopts the support structure for the load measurement sensor according to the related art.
Then, as illustrated in FIG. 28, in order to fix the load measurement sensor 130 to the seat frame 101, a shaft portion 131 (which the '028 Reference describes as a “male screw”) is provided, and the shaft portion 131 is disposed so that its axial direction becomes the vertical direction. In recent years, in order to improve the convenience of the passenger who sits on the vehicle or in the design of the vehicle, a technique is demanded which lowers the height of the vehicle seat. However, in a case where the load measurement sensor 130 is installed with such a technique, the seat frame 101 increases in height by the height of the load measurement sensor 130, which causes a problem in which the height of the vehicle seat increases. FIG. 28 is a cross-sectional view illustrating the support structure for the load measurement sensor according to the related art.
On the other hand, there is proposed a technique in which the shaft portion is disposed so that the axial direction of the shaft portion for attaching the load measurement sensor thereto is not set as the vertical direction, but is set as the horizontal direction (see Japanese Patent Document No. P2010-42809A (“the '809 Reference”)).
In the '809 Reference, the load measurement sensor (which it describes as a “load detection sensor”) is installed so that the axial direction becomes the horizontal direction and the load measurement sensor is disposed to be settled in the height range of the seat frame. For this reason, the height of the vehicle seat may be lowered compared to the technique of the '028 Reference.
In the technique disclosed in the '809 Reference, the load measurement sensor is fixed across the first bracket and the second bracket, so that the axial direction of the load measurement sensor is disposed to be the horizontal direction. However, in the load measurement sensor of the '809 Reference, when a load generated from the seat frame is transmitted to the load measurement sensor, the load measurement sensor may not move in the axial direction with respect to the first bracket and the second bracket since both ends of the load measurement sensor are respectively fixed to the first bracket and the second bracket. As a result, a large load is applied to the attachment portion (the portion of the male screw) of the load measurement sensor, which causes a problem in which the durability is degraded.
Accordingly, a support structure for a load measurement sensor has been needed which has sufficient durability without adding a large load to a portion (member) transmitting a load to a load measurement sensor.
Further, in the technique disclosed in the '809 Reference, both ends of the load measurement sensor in the axial direction are respectively supported to the first bracket and the second bracket through a first damper and a second damper, and a load generated from the first bracket and the second bracket is transmitted to the load measurement sensor. Then, the first damper and the second damper are respectively formed separately from the first bracket and the second bracket, and are individually installed when the load measurement sensor is installed. Accordingly, the first damper and the second damper are not respectively integrated with the first bracket and the second bracket, which has a possibility that an error in position may occur during the attachment operation. As a result, there is a problem in which a measurement error may occur during the load detection.
Further, in the technique of the '809 Reference, the first damper and the second damper are respectively provided between the load measurement sensor and first and second brackets, and the first damper and the second damper are formed by an elastic member, such as a rubber member. In this way, since the first damper and the second damper which are formed by the elastic member absorbs the load generated from the seat frame, the load generated from the seat frame is not completely transmitted to the load measurement sensor, which causes a problem in which it is difficult to accurately detect the load.
In addition, in the load measurement sensor of the '809 Reference, when the load generated from the seat frame is transmitted to the load measurement sensor, the first bracket (or the second bracket) is slightly inclined from the load transmission direction with respect to the shaft portion (the portion of the male screw) of the load measurement sensor, and a part of the first bracket (or the second bracket) is bent, the load is not accurately transmitted to the load measurement sensor, which causes a problem in which a load detection error may occur.
Accordingly, a technique of improving load detection precision by reducing a load detection error has been needed.
In addition, in the technique of the '809 Reference, when the load generated from the seat frame is transmitted to the load measurement sensor, the load measurement sensor may not move in the axial direction with respect to the first bracket and the second bracket since both ends of the load measurement sensor are respectively fixed to the first bracket and the second bracket. As a result, a large load is applied to the attachment portion (the portion of the male screw) of the load measurement sensor, which causes a problem in which the durability is degraded.
Accordingly, a support structure for a load measurement sensor has been needed which has sufficient durability without adding a large load to a portion (member) transmitting a load to a load measurement sensor.
In addition, in a case where both ends of the load measurement sensor are respectively fastened to the first bracket and the second bracket, there are two fastening positions, which causes a problem in which a time necessary for the operation of the load measurement sensor is prolonged.
Accordingly, a technique capable of shortening an operation time by improving the workability during the load measurement sensor attachment operation has been needed.
In addition, in a case where both ends of the load measurement sensor need to be respectively fastened to the first bracket and the second bracket, there is a problem in which the support structure for the load measurement sensor increases in size. Accordingly, in the support structure for the load measurement sensor, a technique of compactly attaching a load measurement sensor in a minimum space has been demanded.
Furthermore, in the load measurement sensor, the sensor body is generally provided with a conversion unit having a substrate which detects a deformation amount (a displacement amount) when receiving a load and converts the deformation amount into an electric signal. Accordingly, since the portion (a part of the seat frame) inputting (transmitting) the load generated from the seat frame to the load measurement sensor and the conversion unit are vicinally provided in many cases, the seat frame and the conversion unit interfere with each other. As a result, there is a problem in which a measurement error may occur. Accordingly, a technique of improving load detection precision by inhibiting interference between a seat frame and a conversion unit to reduce a load detection error has been needed.
Further, a configuration may be supposed in which the load measurement sensor moves to deform the deformation portion provided in the sensor when transmitting the load of the seat from the load input portion to the load measurement sensor. In such a configuration, the load measurement sensor detects the load based on the deformation amount of the deformation portion. However, when the load input from the load input portion is not appropriately transmitted to the deformation portion, the deformation portion is not easily deformed. Accordingly, even when the load is input from the load input portion, the load measurement sensor may not appropriately detect the load.
It is an object of various embodiments of the invention to provide a support structure for a load measurement sensor having sufficient durability without adding a large load to a portion (member) transmitting a load to the load measurement sensor.
Further, it is another object to provide a support structure for a load measurement sensor capable of reducing a load detection error.
Further, it is another object to provide a support structure for a load measurement sensor having sufficient durability.
In addition, it is another object to provide a support structure for a load measurement sensor capable of shortening an operation time when supporting the load measurement sensor to a support bracket.
In addition, it is another object to provide a support structure for a load measurement sensor capable of supporting the load measurement sensor in a small space without increasing a peripheral structure thereof when supporting the load measurement sensor to a support bracket.
In addition, it is another object to provide a support structure for a load measurement sensor capable of accurately detecting an input load by reliably transmitting the load input from a load input portion provided in a seat to the load measurement sensor.